Telephone call indicator



'March l0, 1942. E C, MATTHEWS 4 2,275,539'

TELEPHONE CALL INDICATOR Filed July ll, 1940 l /N VEA/70p E C. MA TTHEWS Afro/MEL Patented Mar. 10, 1942 TELEPHONE CALL INDICATOR Emil C. Matthews, Elizabeth, N. J., assignor` to Bell Telephone Laboratories,

Incorporated,

New York, N. Y., a corporation of New York Application July 11, 1940, Serial No. 344,863

4 Claims.

This invention relates to visual signaling devices and particularly to visual telephone call indicators of the type intended for use, either separately or in combination with audible ringers employed extensively at subscribers stations.

It is the object of this invention to provide an improved visual call indicator which is simple in design, compact in structure, neat in appearance, inexpensive to manufacture and which is capable of withstanding relatively rough usage.

This object is attained in accordance With a feature of the invention by the provision of a simplied mounting for the light emitting element of the indicator which renders it possible to resiliently but firmly support the lamp with a minimum number of parts. Another feature of the invention resides in the provision of a cushion between the frangible tube envelope and the interior wall of the indicator housing which serves to protect the tube against breakage should the indicator be dropped or otherwise mishandled.

The invention will be readily understood from the following detailed description made with reference to the accompanying drawing in which:

Fig. l is a perspective View of a combined telephone handset and an indicator of the present invention which may be associated therewith through the medium of a cord;

Fig. 2 is an elevation of the indicator with certain portions of the housing and lens broken 'A' away to disclose the interior construction and the relative positions of the various elements which make up the indicator;

Fig. 3 is a section taken along the line 3-3 of Fig. 2 looking in the direction of the arrows; and

Fig. 4 is a fragmentary view of a section taken along the line 4 4 of Fig. 3 looking in the direction of the arrows.

The specific embodiment of the invention disclosed in the drawing comprises a tube or bulb 'i III whose stem end is provided with an insulating sleeve II. The tube envelope may be secured in position in the insulating sleeve II in any suitable manner, preferably by cementing. The upper edge of the sleeve II is provided with two The socket for the tube structure described above consists of two substantially circular insulating plates I5 and I6, the latter being smaller in diameter and provided with two oppositely disposed winged portions. The tWo insulators I5 and I6 are secured together by means of a pair of oppositely disposed eyelets I4 and are held in spaced relation by means of two washers I8, each of which fits over the shank of its respective eyelet. interposed between the upper face of the insulator IIi and the upper rim of each of the eyelets I4 is a metal spring clamp I3 consisting of a flat portion apertured to receive the eyelet, and an elongated projection extending vertically therefrom and terminating in an integral inturned portion constituting a clamp or clip. Normally, the two spring clamps I3 are slightly tensioned towards each other and must be distended or separated to permit the sleeve II of the tube Ill to pass therebetween. When the tube is in position in the socket, the hooked ends of the spring clamps I3 snap into the slots I2 in the sleeve II to firmly hold the tube in position.

The upper insulator IB is provided with a centrally disposed circular opening or orifice 2U which is slightly larger in diameter than the diameter of the sleeve il of the tube, so as to permit the sleeve to pass therethrough without binding. A spring I9, which serves as a resilient seat for the tube, is located between the two insulators I5 and I6 and spans the underside of the circular opening in the latter. This spring is loosely held in position by4 virtue of an oblong opening in either end thereof which lits over the spacing washers i8. When the tube is in position, the spring clamps I3 hold it firmly on the spring seat I8, the latter permitting slight Vertical displacement oi the tube, thus acting to absorb shocks to which the tube may be subjected.

Interposed between the upper face of the insulator I5 and each of the washers I8 is a clamp spring Il, which as will be described later, serves to lock the socket and its tube to the indicator housing.

From the description so far advanced, it will be observed that the oppositely disposed eyelets I4 serve to effect a unitary structure comprising the two insulators I5 and I6, the spring clamps I3, the spring seat I 9 and the clip springs I'I. The spring clamps I3 and clip springs I'I are prevented from rotational movement about the eyelet shanks by virtue of small detents or offset projections which nt into suitably located holes in the insulators I6 and I5. The offset projection 5| of one of the clips I'I is clearly shown at the lower left corner of Fig. 4, while the oset projection 52 of one of clamps I3 is shown at the lower left corner of Fig. 2. These projections are bent downwardly from the ends of their respective main portions so as to extend into suitably dimensioned holes or slots in the insulators I5 and I6.

The upper insulator I5 also carries a resistance element 42, which is included in the tube circuit, and also terminals 44 and their associated terminal screws 45 by means of which connections to the cord 4l (Fig. l) may be made. The leads from lamp It are soldered or otherwise secured Vto left-handterminal 44 and the left-hand terminal of resistor 42, respectively, the other terminal of resistor 42 being soldered or otherwise secured to the right-hand terminal 44'.

The indicator housing comprises a molded cr die-'cast base 3l) which is in the form of a truncated cone having an octagonal bottom and corresponding sloping sides. At each of two opposite points near its bottom, the base 3E! is provided with a pin 4i) projecting inwardly. These pins .cooperate with the spring clips Il in effecting a union between the base 3D and the tube socket. Each spring clip is provided with a curved section which snaps over the pin 4i] when the latter is guided under the clip by rotating the base relative to the socket.

Near its upper edge the housing Si) is provided with an internally extending circular flange 3| which serves as a means for supporting the lens holder 32.

iiange of the beehive lens 35, and a plurality of depending sections 34 which are bent under the iiange 3| of the housing 30 to thus mount the holder on the housing.

The relative positions of the various elements of the indicator, so far described, are such that the tube projects vertically from the center of its socket so that the glass envelope projects into the hollow of the lens 36 and is centrally disposed therein. Due to the resilent nature of the tube mounting, the possibility of tube breakage due to shock is minimized. However, to further guard against tube breakage which would otherwise occur should the indicator be dropped in such a manner that the glass envelope would strike against the inside wall of the lens, a soft rubber washer 58 is provided which fits into the area dened by the periphery of the housing fiange 3l and constitutes a collar for the tube lil. This washer serves as a resilient spacer for the tube II) and acts asa cushion to absorb any lateral shocks to which the indicator may be subjected and to prevent contact between the tube envelope and the lens should the indicator be dropped or otherwise mishandled.

A felt or composition pad 39 is adhesively secured to the lower rim of the housing 30 to protect the surface upon which the indicator may rest and also to minimize slippage of the indicator.

As shown in Fig. l, the .indicator is provided with a cord 4l which electrically connects the tube to the handset 5G directly, or may associate the indicator with the set by way of a terminal block. The circuit connections are such that the tube is lighted when ringing current is applied to the line with which the handset is associated.

Though there is disclosed but one embodiment of the invention which involves a single lamp signal, it is to be understood that the struc- The lens holder is circular and con sists of a concave rim which accommodates a tural features hereinbefore set forth are readily applicable to a signal design involving two, three or more signals in a single housing and having individual lenses.

What is claimed is:

l. A call indicator comprising a visual signal having a glass bulb and a sleeve affixed thereto, a socket for supporting said bulb in an upright position including means mounted thereon and embracing the sleeve of said signal, a housing upon which said socket is removably mounted having yan opening at one end through which the glass bulb of said signal extends, a lens, means for holding said lens on said housing so as to enclose the opening in said housing and cover said glass bulb, and means comprising a cushion interposed between said glass bulb and said lens holder for maintaining said glass bulb resiliently spaced from said housing and said lens.

2. A call indicator comprising a visual signal having a glass bulb and a cylindrical sleeve into which said bulb is sealed in an upright position, a socket for said bulb comprising a pai-r of insulators spaced one from the other, one of said insulators having a centrally located oriiice of slightly greater diameter than the diameter of said sleeve, a spring loosely mounted in the spacing between said insulators and disposed immediately below the orifice in said one insulator, said spring constituting a seat for the cylindrical sleeve of said signal, means secured to said one insulator for clamping said sleeve to said spring seat in the orifice of said one insulator, a housing for said socket, a lens carried by said housing so as to cover said glass bulb, and means for maintaining said bulb in a centrally disposed position relative to the interior of said lens, comprising a soft washer interposed between said bulb and said housing and having a centrally located aperture through which said glass bulb extends into the interior of said lens.

3. The combination in a call indicator, of a lamp signal comprising a glass envelope, a tubular support into which the glass envelope extends, a mounting for said support, a housing for said support mounting of greater depth than the depth of said support and having a circular flange located near the upper edge thereof, a lens holder supported by said housing flange, a lens carried by said holder so as to enclose the glass envelope of said lamp signal, and a spacer element interposed between the flange of said housing and the envelope of said lamp signal comprising a washer having a centrally located aperture through which the envelope extends.

4. A unitary socket for a signal lamp having a tubular support into which the lamp is sealed in an upright position, comprising a circular insulating plate, a second insulating plate disposed above said first plate, a pair of washers interposed between said plates to maintain them in spaced relation, said second plate having an aperture through which the tubular support protrudes, a at spring seat, upon which said tubular support rests, located in the spacing between said insulating plates, a pair of clamping devices for holding said tubular support on said spring seat, and means comprising a pair of eyelets, each of which passes through aligned holes in said insulating plates, in one of said spacing washers, in one of said clamping devices and in said spring seat for uniting said socket elements in a unitary structure.

EMIL C. MATTHEWS. 

